JP3024077B2 - Light polarizing device and projector including light polarizing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light polarizing device for forming a plurality of linearly polarized lights having different colors from each other, and a projector provided with the light polarizing device. 2. Description of the Related Art As a conventional liquid crystal display projector, a configuration as shown in FIG. 2 is known. That is, the white light generated from the light source 1 is
When the light is incident on the dichroic prism 3 through the LCD, it is divided into red, green, and blue. Are modulated as transmittance changes, and the modulated red, green, and blue components are combined by a dichroic mirror 8 and projected onto a screen 10 by a projection lens 9. [0003] In the above-mentioned conventional example, the liquid crystal displays 5, 6, and 7 are composed of a polarizing plate and a liquid crystal layer arranged at right angles in order to take advantage of its characteristics. Accordingly, among the red, green, and blue components, those having a polarization direction parallel to the polarizing plate pass, but those having the vertical direction are blocked and absorbed. Such a type has a problem that the light use efficiency does not become 50% or more and the illuminance of the screen is low. If the light source 1 or the lenses 2 and 9 are changed to large ones in order to increase the screen illuminance, the device becomes heavy and expensive. The present invention has been made in view of the above-mentioned problems of the prior art, for example, by using an optical polarizing device capable of increasing the amount of light used in a liquid crystal display while using the same light source and lens as in the prior art, and using the optical polarizing device. An object is to provide a projector with improved light use efficiency. [0005] In order to achieve the above object, the present invention provides an optical polarizing device for forming a plurality of polarized lights having different colors from each other. A beam splitter for splitting into two polarization components, polarization direction changing means for matching the polarization direction of one of the two polarization components with the polarization direction of the other polarization component, and the one polarization component; A deflecting means for aligning the traveling direction of the other polarized light component is provided for each light of each color. The present invention also provides a projector
As the light polarizing device of the above configuration, the device from this device
LCD display illuminated by polarized light of each color
Is what you do. A first aspect of the present invention is an optical polarizing device for forming a plurality of polarized lights having different colors from each other, and divides incident light into two polarized components whose polarization directions are orthogonal to each other. A beam splitter, a polarization direction changing means for matching the polarization direction of one of the two polarization components with the polarization direction of the other polarization component, and the polarization direction changing means for the one polarization component and the other polarization component. By providing a deflecting means for aligning the traveling direction for each light of each color, and since each color light is red light, green light and blue light, the polarization directions of the respective color lights are mutually Since two orthogonal polarization components can be used, light use efficiency can be significantly improved.
According to a second aspect of the present invention , as a projector, the light polarization
By having an optical device and a liquid crystal display illuminated by the polarized light of each color from the device , for example, when a three-panel liquid crystal display projector is configured,
The brightness on the screen is improved and the weight is also improved. An embodiment of the present invention will be described below with reference to FIG. 11 is a light source and 12 is a condenser lens. Reference numerals 13, 14, and 15 denote light polarizing elements serving as light polarizing devices.
Vertical polarization components whose polarization directions are orthogonal to each other.
(Hereinafter referred to as “vertical component”) and parallel polarization component (hereinafter referred to as “vertical component”).
The polarization beam splitter 13a and the polarization beam splitter 13b and the polarization beam splitter 13a, 1 functioning as deflecting means.
A polarization direction changing means sandwiched 3b 90 of ° rotation T
The light polarizing element 14 is formed of an N liquid crystal 13c, and the light polarizing element 14 converts green light having wavelength characteristics of 500 to
Are divided into a perpendicular component and a parallel component which are orthogonal to each other, and a polarizing beam splitter 14b and a polarizing beam splitter 14 functioning as deflecting means.
a, it is formed from the polarization direction change means a is 90 ° rotation of the TN liquid crystal 14c sandwiched 14b, the light polarizing element 15 is polarized from each other light of a wavelength characteristic of 400~500μm blue light
A polarizing beam splitter 15a that divides a light component into a perpendicular component and a parallel component that are orthogonal to each other, and a polarizing beam splitter 15b that functions as a deflecting unit and a polarizing direction changing unit 90 that is sandwiched between the polarizing beam splitters 15a and 15b.
It is formed from a TN liquid crystal 15c that rotates by an angle. 16,1
Reference numerals 7 and 18 denote liquid crystal displays, each of which has a light polarizing element 1.
Red, green, and blue components are modulated from 3, 14, and 15, respectively. In this embodiment having the above configuration, the light source 11
Is incident on the polarizing beam splitter 13a via the condenser lens 12, the vertical component Rs of the red component of the white light is reflected, and the parallel component, the green component, and the blue component pass through as they are. The reflected vertical component Rs of the red component is incident on the liquid crystal display 16, and the parallel component of the passed red component is incident on the TN liquid crystal 13c, but the molecules of the TN liquid crystal 13c remain twisted by 90 °. This parallel component also passes along the torsion, and finally comes out as a vertical component Rs. The vertical component Rs of the red component is used as the polarization beam splitter 13.
b and is incident on the liquid crystal display 16. Further, the light of the green component and the light of the blue component that have passed through the polarizing beam splitter 13b enter the polarizing beam splitter 14a, but the vertical component Gs of the green component is reflected, and the parallel component and the blue component pass through as they are. ,
After passing through the TN liquid crystal 14c, the parallel component becomes a vertical component Gs, and then is reflected by the polarizing beam splitter 14b.
Is incident on. The blue component light that has passed through the polarizing beam splitter 14b enters the polarizing beam splitter 15a, its vertical component Bs is reflected, its parallel component passes through the polarizing beam splitter 15a, and the TN liquid crystal 1
After being converted into a vertical component Bs by 5c, it is reflected by the polarization beam splitter 15b, and both the vertical components Bs enter the liquid crystal display 18. Note that components other than the vertical and parallel components of the red, green, and blue components pass through the polarization beam splitter 15b. By using such a light polarizing element, conventionally,
The amount of incident light, which was suppressed to 50% or less by the polarizing plate of the liquid crystal display, was multiplied, and as a result, the transmittance of the liquid crystal display was increased, so that the screen illuminance was approximately doubled without changing the light source and lens. become. Further, regardless of the use of the polarizing plate of the liquid crystal display, deterioration caused by heat absorption due to the use of the polarizing plate is reduced, and the life and color reproducibility of the liquid crystal display are improved. When the parallel component of light is converted to a vertical component, the wavelength range does not have to be strict if a TN liquid crystal is used instead of a wave plate. As described above, the light polarizing device of the present invention is a device for forming a plurality of polarized lights having different colors from each other, and converts incident light into two polarized lights whose polarization directions are orthogonal to each other.
A beam splitter for splitting the component, the polarization direction changing means for matching the polarization direction of one polarization direction and the other polarization component of the polarization components of of said two polarization components, before
The traveling directions of the one polarized light component and the other polarized light component are aligned.
In addition, by providing a deflecting means for each color light, and since each color light is a red light, a green light and a blue light, light use efficiency can be improved. Further, the projector of the present invention uses the light polarization device and two polarization components in which the polarization directions of the respective colors match.
By having an illuminated liquid crystal display , it is possible to improve the brightness on the screen as a three-panel liquid crystal display projector , for example.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a liquid crystal display projector including a light polarizing device according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a conventional liquid crystal display projector. [Explanation of Signs] 11. Light source, 12. Condenser lens, 13, 1
4, 15,... Light polarizing element, 13a, 14a, 15a,.
Polarizing beam splitter, 13b, 14b, 15b ...
Polarization beam splitter (deflection means), 13c, 14
c, 15c TN liquid crystal ( polarization direction changing means ), 16,
17, 18 ... Liquid crystal display.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 9/31 G02B 5/30 G02F 1/13 505 G03B 21/00

Claims (1)

(57) [Claims] ( 1 ) An apparatus for forming a plurality of polarized lights having different colors from each other, comprising: a beam splitter for dividing incident light into two polarized components whose polarization directions are orthogonal to each other; Polarization direction changing means for matching the polarization direction of one polarization component of the components with the polarization direction of the other polarization component; and deflection means for aligning the traveling directions of the one polarization component and the other polarization component. And a light polarizing device provided for each light of each color. 2. The light polarizing device according to claim 1, wherein each of the color lights is red light, green light, and blue light. (3) Two polarized light components whose polarization directions are orthogonal to each other
Beam splitter and the two polarization components
The polarization direction of one polarization component and the polarization of the other polarization component
Polarization direction changing means for matching the directions and the one
To align the traveling direction of the polarized light component and the other polarized light component
Deflecting means for each color of light to provide
A light polarizing device for forming a number of polarized light beams, and
A liquid crystal display illuminated by the polarized lights of the respective colors . 4 wherein each color light is a red light and green light and blue light
The project according to claim 3, characterized in that:
Doctor.